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Four new chiral stationary phases based on mono-(6A-allylcarbamido-6A-deoxy)-arylcarbamoylated β-cyclodextrin were synthesized. The chiral stationary phase of phenylcarbamoylated β-cyclodextrin exhibited excellent separation capability for a variety of chiral compounds. Compared with the previous work, it was found that the spacer remained on the surface of the silica gel and decreased the enantioseparation capability. 相似文献
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Samples resulting from reaction of TiO2 with octyltriethoxysilane, developed using a supercritical carbon dioxide procedure, have been studied by infrared and Raman spectroscopies and thermogravimetric analysis. Different reaction conditions have been applied to the preparation of samples in order to study the influence of experimental factors on the sample properties. Vibrational techniques have first been used to verify the presence of silanized structures on the surface of TiO2 through the detection of specific bands characteristic of the Si-O-Si cross-linking. Thermogravimetric profiles consisting of weight loss values as a function of temperature have been analyzed by principal component analysis to extract information about the characteristics of the linkage between silane and TiO2 as well as the thermal stability of the prepared materials. The mathematical treatment of data has provided conclusions on the properties of the samples and analogies and differences with respect to the commercial material. 相似文献
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Durable superhydrophobic cellulose fabric was prepared from water glass and n-octadecyltriethoxysilane (ODTES) with 3-glycidyloxypropyltrimethoxysilane (GPTMS) as crosslinker by sol-gel method. The result showed that the addition of GPTMS could result in a better fixation of silica coating from water glass on cellulose fabric. The silanization of hydrolyzed ODTES at different temperatures and times was studied and optimized. The results showed that silanization time was more important than temperature in forming durable hydrophobic surface. The durability of superhydrophobicity treatment was analyzed by XPS. As a result, the superhydrophobic cotton treated under the optimal condition still remained hydrophobic properties after 50 washing cycles. 相似文献
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Dehydration of Castor Oil over NaHSO4/MCM‐41 Catalyst Modified by n‐Dodecyltriethoxysilane
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Cui‐Xia Yan Jian‐Fei Ding Tian‐Lin Ma Rong Shao Wei Xu Jie He Peng‐Fei Wang 《无机化学与普通化学杂志》2017,643(12):772-779
n‐Dodecyltriethoxysilane (DTEOS) modified NaHSO4/MCM‐41 catalysts (silanized catalysts) were synthesized by different impregnation sequences and evaluated in the liquid‐phase dehydration of castor oil. The samples were evaluated by X‐ray diffraction, nitrogen adsorption‐desorption, SEM, TEM, FT‐IR spectroscopy, XPS, 29Si MAS NMR spectroscopy, contact angle measurements, NH3‐TPD, and pyridine‐FT‐IR spectroscopy. The analyses demonstrated that silanization enhanced the hydrophobicity of the catalysts, and the impregnation sequence of silanized catalysts had a significant effect on the NaHSO4 dispersion, surface area, acid distribution, and hydrophobicity of the silanized catalysts. The catalytic activity of the silanized catalysts was much higher than that of NaHSO4/MCM‐41. Among the silanized catalysts, the catalyst prepared by simultaneous impregnation with DTEOS and NaHSO4 showed the highest iodine value of 141.8 [g(I2) per 100 g] and lowest hydroxyl value of 11.3 [mg(KOH) · g–1]. 相似文献
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Functionalization of Silicon Nanoparticles via Silanization: Alkyl, Halide and Ester 总被引:2,自引:0,他引:2
The feasibility of using silanization as a general tool to functionalize the surface of silicon nanoparticles (NPs) has been
investigated in detail. Silicon NPs were prepared from reduction of silicon tetrachloride with sodium naphthalide. The terminal
chloride on the surface of as-synthesized particles was substituted by methanol and water, in sequence. The particles were
then silanized by octyltrichlorosilane, 11-bromoundecyltrichlorosilane, or 2-(carbomethoxy)ethyltrichlorosilane. These treatments
yielded alkyl-, bromo-, or ester-termini on NP surfaces, respectively. The NPs were characterized by TEM, NMR, FTIR, UV–Vis,
and PL spectroscopy. Changes of termination groups brought various functionalities to the NPs, without loss of the photophysics
of the original NPs. 相似文献
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The influence of glass surface modification in order to determine strength of the monolith attachment was studied. Modification consists of pre-treatment of the glass with chemicals or boiling in deionized water, silanization and drying has been investigated on different types of glass. Amount of silane groups was determined by measurement of the contact angle between the glass surface and water drop. The highest values were found for soda-lime glass. Strength of the monolith attachment was established by pumping ethanol through the monolithic capillaries and measuring the pressure drop at which monolith was dislodged. Surprisingly, it was found that the critical part of the glass surface modification procedure is glass pre-treatment. Good results were obtained with glass boiled in water for 2.5 h or more. 相似文献
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Grossmann F Ehwald V du Fresne von Hohenesche C Unger KK 《Journal of chromatography. A》2001,910(2):218-236
Native mesoporous silica beads were subjected to a sequence of post-treatment procedure including hydrochloric acid treatment, calcination and subsequent rehydroxylation. The post-treated silica beads were converted into RP-18 silica by silanization with monochloro- and dimethoxy-n-octadecylsilanes, respectively. The influence of post-treatments and silanization conditions on the physico–chemical characteristics and on the chromatographic behaviour of the RP-silicas was studied. Also the changes of the pore structural parameters and the silanol group densities during the post-treatment and silanization were assessed. 相似文献
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A simple and fast methodology for protein patterning on silicon substrates is presented, providing an insight into possible issues related to the interaction between biological and microelectronic technologies. The method makes use of standard photoresist lithography and is oriented towards the implementation of biosensors containing Complementary Metal-Oxide-Semiconductor (CMOS) conditioning circuitry. Silicon surfaces with photoresist patterns were prepared and hydroxylated by means of resist- and CMOS backend-compatible solutions. Subsequent aminosilane deposition and resist lift-off in organic solvents resulted into well-controlled amino-terminated geometries. The discussion is focused on resist- and CMOS-compatibility problems related to the used chemicals. Some samples underwent gold nanoparticle (Au NP) labeling and Scanning Electron Microscopy (SEM) observation, in order to investigate the quality of the silane layer. Antibodies were immobilized on other samples, which were subsequently exposed to a fluorescently labeled antigen. Fluorescence microscopy observation showed that this method provides spatially selective immobilization of protein layers onto APTES-patterned silicon samples, while preserving protein reactivity inside the desired areas and low non-specific adsorption elsewhere. Strong covalent biomolecule binding was achieved, giving stable protein layers, which allows stringent binding conditions and a good binding specificity, really useful for biosensing. 相似文献